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what gives more hp/tq

547 Views 12 Replies 9 Participants Last post by  zmonster
a euro damper or a underdrive pully or is it the same
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not the same....a euro pulley is lighter; an underdrive pulley is smaller. The underdrive pulley drives the accessories-water pump, alternator etc at less speed so it frees up a horsepower or two. The euro pulley has only one belt groove so it's lighter and thus slightly reduces rotating mass. Like any such reduction in mass, it doesn't really give more horsepower but it lets the motor rev quicker, but in practice you wouldn't be able to tell the difference between a stock pulley and the euro. You probably won't be able to tell the difference from an underdrive pulley either, like I said, it's a very minor difference. Considering the prices people are getting for either one, I think they should be low on your "things to do to go faster" list....for the cost, there are a lot of other things you can do with a much much higher horsepower/cost ratio....
thanks i got one more ? now i know it prolly wouldnt make a noticable diff but i see in pictures that alot of people dont keep there power steering. does this gain u anything or is it just 1 or 2 wopin hp
Why don't you just get both............the damper for the 240Z is a smaller diameter pulley than the 280 unit, that still will work with the stock 280 V-belt. So get yourself a Euro damper that's made for a 240Z and you will get both a lighter weight, single groove pulley, and a underdrive pulley by being a smaller diameter.
Z's didn't have power steering from the factory, ZX's were the ones with power steering. Some have switched from p.s to manual racks on there zx's.
Isn't an underdrive pulley larger so it spins the accessory slower??? (e.g. alternator) It it were smaller it would spin faster.
Post Edited (Nov 16, 3:40pm)
or is it just 1 or 2 wopin hp

you wont get any more than that from any crank pulley you put on.
GumbyZ13 and Spudea, think about which pulley would feed more belt at the same RPM. One revolution on the big pulley would drive the belt farther than the small one which in turn, would turn the alternator and WP FASTER, not slower. Do the math. You are right in one respect, a larger pulley on the alternator or water pump will slow them down, but we are talking about the drive pulley, not the accesory pulleys.
I like the euro damper better. I've heard that underdrive pullies can mess the engine up by disrupting the balance of the engine. Not sure if there is any truth to it but from what I've read it makes sense in a general way; wheather it means anything on the Z engine I don't know. What I do know is that after I installed the euro damper on my 280z I felt a nice difference in the way the car reved. Much faster and responsive. As for hp gains it's only about a 2-3 hp gain from what I've heard. Like others have said it's not that it's making more hp, it's just reducing drag so that more of the engine hp makes it to the rear wheels. It's that whole thing about how rear wheel hp is less than crank hp becuase of drag from different parts. Well of of the ways to reduce drag to get more hp to the rear wheels is lighter crank pullies, lighter flywheels, lighter drive shaft, etc. While at the same time the lighter it is the faster it will rev, so it's a double gain: more hp and faster reving to get to peak hp faster. Still the hp gains are small and reving is only decently better. A lighter flywheel I heard is much more effective but I've heard that both together make for a nice reving engine. As for the power steering it would be good to remove it but again minor gains and slightly better reving. Essentialy anything that is creating drag on the motor is keeping the hp to get to the rear wheels so in a sense if you at one time did a euro damper, lighter flywheel, removed power steering, and got a lighter driveshaft you would notice a big difference in the way the car reved and would probably get a decent gain in hp at the rear wheels. It's like the whole intake, exhuast, and header thing. Alone they don't do much but do them all at once and you'll notice a nice difference. The euro damper is just another piece of the puzzle to building an engine. Alone it won't do much but in series with other mods it helps. If you haven't done some of the other basic stuff I would hold off on it until then.
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Yes, I realize if the crank pulley was larger it would in turn spin the accessories faster. However my post was in response to an earlier post which stated:

"an underdrive pulley is smaller. The underdrive pulley drives the accessories-water pump, alternator etc at less speed so it frees up a horsepower or two"

The way I read that it was saying the accessory pulleys were smaller. The majority of times I have heard of someone referring to an underdrive pulley it was mounted to the accessories and not the crank. (Yes I realize there are underdrive crank pulleys as well) That is what I was referring to, perhaps my earlier post did not quite get that across...My bust.

Arizona Z Car has a pretty good looking set of pulleys they sell. I wouldn't mind having a set in blue, and if I had the extra cash...

Underdrive pulleys
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No sweat.
I got a Euro damper, and I will agree I couldn't feel the difference. It seems like it makes a more noticeable difference on stock or close to stock engines than on significantly modified ones. Thats just based on what I heard after I installed mine. Maybe with my 11lb flywheel, etc. it just revs so fast that its not really gonna rev much faster.

I got a much better result from a $40 MSD Blaster 2 coil. I did them within two days of eachother, the MSD coil made a noticeable difference, but who knows - that could have just been due to the fact that the coil I took off was nearly 30 years old.
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